A couple of decades ago coding was "solved" by just writing UML diagrams. The nonsense never ends.

That's a different thing. UML described structure: classes, relations, maybe some state machines. The generators turned that into skeletons, and people still wrote the actual logic by hand.

Here the agent writes the logic too, and 10k tests plus a commit gate check whether it works. In my case that's about 500k lines nobody typed. You can doubt that the approach generalizes, but it's not the same promise as UML.